In recent years, air-suction sheet-supplying device has been used in image forming apparatuses, such as copy machines, printers, or the like, so that the sheets are supplied at high speed. In the air-suction sheet-supplying device, air is blown against the lateral edge of the stacked sheets, so that the sheets float, after that, a single sheet is separated from the floated sheets, and is supplied to a next section.
Unexamined Japanese Patent Application Publication 2006-327,716 discloses an air-suction sheet-supplying device, in which air is blown against the lateral edge of the stacked sheets, so that the top sheets are made to float, whereby the sheets are separated from each other. When a sheet supplying roller supplies the sheet, said sheet is easily separated from the floated sheets.
Generally, image forming apparatuses have been configured to employ various sheets, concerning the size, thickness, and type. Accordingly, the sheet-supplying devices, to be combined to the image forming apparatuses, have been required to exhibit an ability to stably supply the various sheets as needed to the image forming apparatuses.
After the inventor had studied the air-suction sheet-supplying device, the inventor understood that when various sizes of sheets or the various thicknesses of sheets are supplied from the air-suction sheet-supplying device to the image forming apparatus, the capability of floating the sheets varies depending on the size or thickness of the sheets. That is, specific sheets could be floated and supplied as desired, other sheets could not be floated, nor supplied to the image forming apparatus, which resulted in malfunction of the air-suction sheet-supplying device.
Concerning the conventional air-suction sheet-supplying technology, the malfunction, occurred due to the size or thickness of the sheets, has not been studied by manufacturers. Further, the above described patent document does not show a method to overcome said malfunction.
An object of the present invention is to solve said malfunction of the air-suction sheet-supplying device, and to offer a sheet-supplying device, an image forming apparatus, and an image forming system, in which various sheets can be stably conveyed.